Transformer-cooling means



July 8 1924.

R. V. BINGAY TRANSFORMER COOLING mus Filed Sept. I 1922 A TTORNE Y5.

' Patented July 8, 1924.

UNITED STATES PATENT OFFICE.

ROBERT V. BINGAY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH TRANSFORMER COMPANY, A CORPORATION OF PENNSYLVANIA.

TRANSFORMER-COOLING MEANS.

Application filed September 1, 1922. Serial No. 585,615.

To all whom it may concern: 1

Be it known that I, ROBERT V. BINGAY, a citizen of the United States, residing .at Pittsburgh, in the county of Allegheny and State of Pennsylvania, hate invented certain new and useful Improvements in Transforn'ier-Cooling Means, of which the follow- I ing is a specification.

This invention relates to electrical transformers and cooling means therefor and particularly to the provision of cooling apparatus in connection with a tank containing the transformer immersed in a circulating medium such as oil. The object of the invention is to provide simple and inexpensive and efficient cooling means for the circulating medium.

Prior cooling devices for transformer tanks in common use are often complicated in construction and cumbersome in size and usually contain a large amount of dead oil or slowly circulating oil which forms a heavy load on the tank structure and is expensive in first cost and detrimental to the efiiciency of the cooling action. In the cooling means of this invention the oil in the form of a comparatively thin sheet is kept in rapid circulation between closely adjacent surfaces in very efficient manner and with a reduction in the amount of oil required. At the same time the cooling means is itself readily built up from stock parts in inexpensive manner and easily installed in place on the transformer tank. I

In the accompanying drawings illustrating the invention- Fig. 1 is a vertical elevational view of a transformer tank provided with auxiliary cooling apparatus.

Fig. 2 is a plan view of the same.

Fig. 3 is a vertical sectional view of the same.

Fig. 4 is a detached perspective view of a portion of the apparatus shown in Fig. 1, and

Figs. 5 and 6 are vertical and horizontal sectional views respectively of the cooling apparatus illustrating details of construction.

In the specific embodiment of the invention shown in the drawings a tank K contains a transformer T immersed in oil which substantially fills the tank to a level L for instance. The tank may be either plain or corrugated and the oil will be partially cooled by contact with the walls of the tank.

Additional cooling means is provided in the form of auxiliary cooling devices C connected to the tank by pipes 10 above and pipes 11 below so that the hot oil passing in; at the top through connection 10 will circulate downward through the cooling device C and return to the tank through the lower connection 11. This auxiliary cooler C comprises metal plates or sheets 12, 13 spaced apart a short distance so as to pro vide a vertical conduit forming the circulating oil into a relatively thin layer. The hot oil entering at the top through connection 10 is spread out in between the plates 12, 13 which radiate the heat from the oil and thus cool it as it passes downward.

The plates 12, 13 are separated a distance (I just sufiicient to permit the heated oil to circulate very freely and at the same time to require the whole body of oil to move downward together without any dead portions or local eddies. This permits the plates 12, 13 to be relatively close together and since the body or layer of circulating oil between them is very thin from surface to surface in comparison with the width to of the cooling conduit between the plates 12, 13, all'of the oil is kept continuously in direct. contact with the cooling surfaces with no possibility of developing dead or hotportions of the oil remote from the exposed surfaces. The column of oil in the cooler is thus subjected to a maximum of cooling action throughout its entire height.

- To facilitate circulation of oil from the tank K and permit the cooling column to move downward as a whole the pipe connections 10, 11 at top and bottom of each cooler C are made large in cross section, their combined areas being for instance equal to or greater than the cross section area between plates 12. 13.

This auxiliary cooling apparatus therefore with its large radiating surface in proportion to the cross section area of the conduit provides for free circulation of the oil and requires all of it to come into close contact with the cooling plates 12, 13, which throughout their entire extent are exposed to the d rect action of the cooling currents of the surrounding air passing upward along plate 12 and up through between plate 13 and the tank, this space. between the plate 13 andthe tan-k being open at the top.

The cooling devices C may also be constructed simply and inexpensively. Forinstance as shown in Figs. 5 and 6 the two sheets 12 and 13 may simply be welded to rods 15 at the top and bottom while plate 12 is bent around and welded to plate 13 by weld 16 as shown in Fig. 6. The pipe connections 10 and 11 to the tank are then welded in place in the plate 13 and the device as a whole mounted on the tank by welding these connections 10. 11 in holes in the tank body. The body of the cooler C is thus formed by the closely spaced plates joined together for mutual support and forming a strong rigid structure. The close spacing of plates 12. 13 also reduces the amount and weight of the oil thus saving in the amount of oil required and also reducing the total weight of the auxiliary cooling apparatus which is imposed upon the tank structure.

The coolers C may be slightly are shaped to conform to the general contour of the periphery of the tank K as shown in the drawings and successive coolers may be staggered with relation to eachother as shown in dotted lines in Fig. 2 so as to provide for a large number of coolers and still permit them to be separated from each other for ventilation. Another modificatiom-for securing increased radiating surface is shown in the lower half of Fig. 2, in which the sheets are increased in number, the several sheets being supportedby braces 17, which may if desired be in the form of tubes permitting flow of the cooling fluid from one sheet to the other. I

The building of a cooler of this invention involves simply the cutting and welding together of stock metal parts. It is only necessary to cut and bend the side plates 12, 13 and rods 15 and weld these parts together and then weld the pipe connections 10, 11 in place. It is therefore unnecessary to make complicated castings or to carry on hand a large number of patterns for each special size and type of job.

The cooler is not only light in weight. itself but contains only a small body of oil, thus further decreasing the weight and strain on the transformer tank and reducing the quantity of oil required to originally fill the tank and coolers.

In lieu of welding the parts may be fastened by brazing, or in other suitable manner.

1. An apparatus comprising a tank and a cooler spaced from said tank and connected thereto and having metal sides substantially parallel to each other and to said tank and closel spaced with relation to each other so as to orm the circulating oil into a relatively thin downwardly moving sheet between said sides, and pipe connections between the cooler and tank having a combined cross sectional area at least as large as the transverse cross sectional area of the cooler.

2. An apparatus comprising a tank and a plurality of coolers spaced from said tank and each cooler having metal sides substantially parallel to each other and to the adjacent surface of the tank, closely spaced with relation to each other so as to form the circulating oil into a relatively thin downwardly moving sheet between said sides, and pipe connections between each cooler and the tank having a combined cross sectional area at least as large as the transverse cross sectional area of the cooler.

3. A cooler adapted for the circulation of oil, comprising a pair of metal sides substantially parallel to each other and welded together at their edges. said sides being closely spaced withrelation to each other so as to form the oil into a circulating film,

one of said sides being formed with top and bottom openings midway. between its side edges, and short pipe connections from said openings adapted to communicate with the interior of a tank for'the circulation of said oil. a

4. A cooler comprising a pair of metal sides substantially parallel to each other and welded together at their edges, said sides being. closely spaced with relation to each other so as to form a narrow passage for a circulating liquid, and pipe connections for the circulating liquid welded to the top and bottom of one of said sides and adapted to support said cooler from a ta,nk,.said pipe connections having a combined cross "sectional area at least equal to the transverse 1 cross sectional area of said cooler.

5. An auxiliary cooler for the oil of a transformer tank comprising parallel metal plates welded together along their meeting edges, spacer members welded between said plates at their ends and pipe connections welded to one of said plates for the circulation of oil between said tank and said cooler.

6. A tank and auxiliary cooling apparatus comprising an upper horizontally directed pipe connection from the tank to said a paratus, a vertical body portion exten ing downward from said conneiztion and having closely spaced parallel walls providing a narrow passage of the cross sectional area less than twice the cross sectional area of said pipe connection and a lower pipe connection leading from said apparatus to said tank.

ROBERT V. BINGAY. 

